[clang] [clang-format] Fix a crash with AlignArrayOfStructures option (PR #86420)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-format

Author: Owen Pan (owenca)

<details>
<summary>Changes</summary>

Fixes #<!-- -->86109.

---
Full diff: https://github.com/llvm/llvm-project/pull/86420.diff


2 Files Affected:

- (modified) clang/lib/Format/WhitespaceManager.cpp (+1-1) 
- (modified) clang/unittests/Format/FormatTest.cpp (+10) 


``````````diff
diff --git a/clang/lib/Format/WhitespaceManager.cpp b/clang/lib/Format/WhitespaceManager.cpp
index fef85abf79a38c..710bf8d8a8ec70 100644
--- a/clang/lib/Format/WhitespaceManager.cpp
+++ b/clang/lib/Format/WhitespaceManager.cpp
@@ -1491,7 +1491,7 @@ WhitespaceManager::CellDescriptions WhitespaceManager::getCells(unsigned Start,
                                                                 : Cell);
         // Go to the next non-comment and ensure there is a break in front
         const auto *NextNonComment = C.Tok->getNextNonComment();
-        while (NextNonComment->is(tok::comma))
+        while (NextNonComment && NextNonComment->is(tok::comma))
           NextNonComment = NextNonComment->getNextNonComment();
         auto j = i;
         while (j < End && Changes[j].Tok != NextNonComment)
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index cf8d6ab691d9a0..a33520d81b8421 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -21101,6 +21101,11 @@ TEST_F(FormatTest, CatchAlignArrayOfStructuresRightAlignment) {
                 "    [1] { 1, 1, },\n"
                 "    [2] { 1, 1, },\n"
                 "};");
+  verifyNoCrash("test arr[] = {\n"
+                "#define FOO(i) {i, i},\n"
+                "SOME_GENERATOR(FOO)\n"
+                "{2, 2}\n"
+                "};");
 
   verifyFormat("return GradForUnaryCwise(g, {\n"
                "                                {{\"sign\"}, \"Sign\",  "
@@ -21354,6 +21359,11 @@ TEST_F(FormatTest, CatchAlignArrayOfStructuresLeftAlignment) {
                 "    [1] { 1, 1, },\n"
                 "    [2] { 1, 1, },\n"
                 "};");
+  verifyNoCrash("test arr[] = {\n"
+                "#define FOO(i) {i, i},\n"
+                "SOME_GENERATOR(FOO)\n"
+                "{2, 2}\n"
+                "};");
 
   verifyFormat("return GradForUnaryCwise(g, {\n"
                "                                {{\"sign\"}, \"Sign\", {\"x\", "

``````````

</details>


https://github.com/llvm/llvm-project/pull/86420